Cleaning apparatus and image forming apparatus

Abstract

To provide a cleaning device and an image formation apparatus which suppress reduction in the removal performance of toner in comparison to such a constitution that a bristle material of a cleaning brush is brought into contact with a contact member on the downstream side after restoration from deformation due to contact with a contact member on the upstream side.SOLUTION: A cleaning device 60 comprises: a cleaning brush 61 which has a large number of bristle materials 61F brought into contact with the surface of a secondary transfer belt in a rotating manner and removes toner adhering to the surface of the secondary transfer belt; a first contact member 64 which is brought into contact with the bristle materials 61F in such a state that the relative position with the cleaning brush 61 does not change; and a second contact member 66 which is brought into contact with the bristle materials 61F on the downstream side in the rotation direction of the cleaning brush 61 relative to the first contact member 64 in such a state that the relative position with the cleaning brush 61 does not change. The second contact member 66 is arranged on an extension line EL of a root part 62 of the bristle material 61F when being separated from the first contact member 64 and a shaft center 61C of the cleaning brush 61.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a cleaning device and an image forming apparatus.

Background Art

[0002] In Patent Document 1 below, in a charging region for charging the surface of an image carrier that rotates in a predetermined direction, the surface is charged, and an electrostatic latent image is obtained on the surface of the image carrier by irradiating exposure light on the charged surface of the image carrier. The electrostatic latent image is developed with toner to form a toner image on the surface of the image carrier, and the toner image is transferred to a transfer region to be transferred to a transfer surface and finally fixed on a recording medium to form an image composed of a fixed toner image on the recording medium. An image forming apparatus is disclosed that includes a plate-shaped cleaning blade having a tip pressed against the surface of the image carrier and scraping residues from the surface of the image carrier, which is disposed at a position on the downstream side in the rotation direction of the image carrier from the transfer region and on the upstream side in the rotation direction of the image carrier from the charging region; a solid lubricant applied to the surface of the image carrier; a rotating brush that rotates in a predetermined direction through two regions, namely, a region in contact with the surface of the image carrier and a region in contact with the solid lubricant, and is disposed at a position on the downstream side in the rotation direction of the image carrier from the transfer region and on the upstream side in the rotation direction of the image carrier from the cleaning blade, for applying the lubricant to the surface of the image carrier; and a plurality of flicking members arranged side by side in the rotation direction of the rotating brush and knocking off deposits adhering to the brush by biting into the brush.

[0003] Patent Document 2 below discloses a cleaning device comprising a rotatable rotating shaft member and a brush roller section consisting of a plurality of bristles erected on its circumferential surface, wherein the cleaning brush roller scrapes off deposits adhering to the surface of the object to be cleaned with the brush roller section, a recovery member that rotates while in contact with the brush roller section under the applied recovery bias, thereby transferring and recovering deposits within the brush roller section onto its own surface, and a brush contact member disposed to contact a region of the entire circumferential area of ​​the brush roller section when it moves to a predetermined rotation position, wherein the bristles are temporarily bent at the contact position between the brush roller section and the brush contact member, and then the bristles that have passed the contact position are quickly returned to their original position by the stiffness of the brush, thereby shaking off deposits trapped within the brush roller section, wherein the cleaning device is disclosed in which the brush contact member is in contact with a region of the entire circumferential area of ​​the brush roller section that has passed the contact position with the object to be cleaned but has not yet entered the contact position with the recovery member.

[0004] Patent Document 3 discloses a cleaning device having a brush that rotates in contact with the surface of a toner image holder and a toner removal means for removing toner adhering to the brush, wherein the toner removal means comprises a plurality of toner scraping bars and a movable support means that supports the plurality of toner scraping bars and moves each toner scraping bar in a circular motion to a toner scraping position determined so that the amount of penetration into the brush changes. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2005-257844 [Patent Document 2] Japanese Patent Publication No. 2012-237787 [Patent Document 3] Japanese Patent Application Publication No. 05-107997 [Overview of the project] [Problems that the invention aims to solve]

[0006] The purpose of this disclosure is to provide a cleaning device and an image forming apparatus that suppress the decrease in toner removal performance compared to a configuration in which the bristles of the cleaning brush recover from deformation caused by contact with an upstream contact member before contacting a downstream contact member. [Means for solving the problem]

[0007] A cleaning device according to the first embodiment includes a cleaning brush having a number of bristles that rotate and contact the surface of a member to be cleaned to which toner is attached, and which removes the toner attached to the surface of the member to be cleaned; a first contact member that contacts the bristles while its relative position to the cleaning brush does not change; and a second contact member that is located downstream of the first contact member in the rotational direction of the cleaning brush and contacts the bristles while its relative position to the cleaning brush does not change, and the second contact member is positioned on the extension line between the base of the bristles when it separates from the first contact member and the axis center of the cleaning brush.

[0008] The cleaning device according to the second embodiment is the cleaning device according to the first embodiment, wherein the first contact member and the second contact member have a shape in which at least the portion that contacts the bristles is curved in a convex shape along the circumferential direction of the cleaning brush.

[0009] The cleaning device according to the third embodiment is the cleaning device according to the second embodiment, wherein at least one of the first contact member and the second contact member is a cylindrical member.

[0010] The cleaning device according to the fourth embodiment is the cleaning device according to the third embodiment, wherein the first contact member is a cylindrical member, and the device includes a rotating part for rotating the cylindrical member, and at the part opposite to the cleaning brush, the rotation direction of the cleaning brush and the rotation direction of the cylindrical member are in opposite directions.

[0011] The cleaning device according to the fifth embodiment is the cleaning device according to the third or fourth embodiment, wherein the second contact member is a cylindrical member, and the device is equipped with a rotating part for rotating the cylindrical member, and at the part opposite to the cleaning brush, the rotation direction of the cleaning brush and the rotation direction of the cylindrical member are in opposite directions.

[0012] The cleaning device according to the sixth embodiment is the cleaning device according to the third or fourth embodiment, wherein the first contact member is a cylindrical member, and the penetration of the bristles is smaller than the radius of the cylindrical member.

[0013] The cleaning device according to the seventh embodiment is a cleaning device according to any one embodiment from the first to the sixth embodiment, wherein the amount of penetration of the second contact member into the bristles is less than or equal to the amount of penetration of the first contact member into the bristles.

[0014] The cleaning device according to the eighth embodiment is a cleaning device according to any one of the first to seventh embodiments, wherein the support portion that supports the first contact member and the second contact member is electrically insulated.

[0015] The image forming apparatus according to the ninth embodiment includes a toner transporter which is a toner holding member that holds a toner image, or a transfer member that transfers a toner image to a recording medium nipped between itself and the toner holding member, and a cleaning device according to any one of the first to eighth embodiments for cleaning toner adhering to the surface of the toner transporter. [Effects of the Invention]

[0016] According to the cleaning device of the first embodiment, compared to a configuration in which the bristles of the cleaning brush recover from deformation caused by contact with an upstream contact member before contacting a downstream contact member, a decrease in toner removal performance can be suppressed.

[0017] According to the cleaning device according to the second aspect, the bristles of the cleaning brush are more likely to bend when contacting the first contact member and the second contact member due to the rotation of the cleaning brush, as compared with the case where the first contact member and the second contact member are rectangular.

[0018] According to the cleaning device according to the third aspect, the positioning of the first contact member and the second contact member is easier, as compared with the case where only a part of the first contact member and the second contact member is circular.

[0019] According to the cleaning device according to the fourth aspect, toner is more easily removed from the bristles of the cleaning brush, as compared with the case where the first contact member, which is a columnar member, is fixed.

[0020] According to the cleaning device according to the fifth aspect, toner is more easily removed from the bristles of the cleaning brush, as compared with the case where the second contact member, which is a columnar member, is fixed.

[0021] According to the cleaning device according to the sixth aspect, when the bristles of the cleaning brush contact the second contact member after leaving the first contact member, the impact is greater, as compared with the case where the penetration of the bristles of the cleaning brush is greater than the radius of the columnar member.

[0022] According to the cleaning device according to the seventh aspect, the amount of deflection of the bristles when the first contact member contacts the bristles is greater than or equal to the amount of deflection of the bristles when the second contact member contacts the bristles.

[0023] According to the cleaning device according to the eighth aspect, the adhesion of the charged toner from the support portion to the first contact member and the second contact member is suppressed, as compared with the case where the support portion supporting the first contact member and the second contact member is charged.

[0024] According to the image forming apparatus according to the ninth aspect, the occurrence of contamination of the recording medium by toner is suppressed, as compared with the configuration in which the bristles of the cleaning brush contact the downstream contact member after recovering from the deformation due to the contact with the upstream contact member.

Brief Description of the Drawings

[0025] [Figure 1] This is a schematic diagram showing an example of an image forming apparatus equipped with a cleaning device according to the first embodiment, viewed from the front. [Figure 2] This is a schematic diagram showing the toner image forming section of an image forming apparatus. [Figure 3] This is a schematic diagram showing a part of the cleaning device and transfer device according to the first embodiment. [Figure 4] This is a schematic diagram showing a cleaning device according to the first embodiment. [Figure 5] (A), (B), and (C) are schematic diagrams showing, in order, the steps for removing toner from the cleaning brush of the cleaning device according to the first embodiment. [Figure 6] This is a schematic diagram showing the main parts of an image forming apparatus equipped with a cleaning device according to the second embodiment. [Figure 7] (A), (B), and (C) are schematic diagrams showing, in order, the steps for removing toner from the cleaning brush of a cleaning device according to a comparative example. [Modes for carrying out the invention]

[0026] An example of an embodiment of this disclosure will be described below with reference to the drawings. In each figure, arrow H indicates the vertical direction, and arrow W indicates the horizontal direction, which is the width direction of the device.

[0027] [First Embodiment] <Configuration of the image forming apparatus 10> Figure 1 is a schematic diagram showing an example of an image forming apparatus 10 equipped with a cleaning device 60 according to the first embodiment. As shown in Figure 1, the image forming apparatus 10 includes an image forming unit 12 that forms an image on a recording medium P such as paper using an electrophotographic method, a transport device 50 that transports the recording medium P, and a control unit 70 that controls the operation of each part of the image forming apparatus 10.

[0028] (Conveying device 50) As shown in Figure 1, the transport device 50 includes a container 51 in which the recording medium P is housed, and a plurality of transport rolls 52 that transport the recording medium P from the container 51 to the secondary transfer position NT. Furthermore, the transport device 50 includes a plurality of transport belts 58 that transport the recording medium P from the secondary transfer position NT to the fixing device 40, and a transport belt 54 that transports the recording medium P from the fixing device 40 toward the recording medium P discharge section (not shown).

[0029] (Image forming unit 12) The image forming unit 12 includes a toner image forming unit 20 that forms a toner image, a transfer device 30 that transfers the toner image formed by the toner image forming unit 20 to a recording medium P, and a fixing device 40 that heats and pressurizes the toner image transferred to the recording medium P to fix it to the recording medium P.

[0030] Multiple toner image forming units 20 are provided to form toner images for each color. In this embodiment, a total of four toner image forming units 20 are provided for yellow (Y), magenta (M), cyan (C), and black (K). These toner image forming units 20 for each color are arranged in the order of yellow (Y), magenta (M), cyan (C), and black (K), from the upstream side to the downstream side in the transport direction of the intermediate transfer belt 31, which will be described later.

[0031] Figure 1 shows (Y), (M), (C), and (K) to indicate the component parts corresponding to each of the above colors. In this specification, the parentheses around (Y), (M), (C), and (K) may be omitted, and they may be written as Y, M, C, and K.

[0032] [Toner image forming unit 20] Each toner image forming unit 20 is basically configured similarly, except for the toner used. Specifically, as shown in Figure 2, each toner image forming unit 20 includes a photoreceptor drum 21 that rotates clockwise in Figure 2, a charger 22 that charges the photoreceptor drum 21, and an exposure device 23 that exposes the photoreceptor drum 21 charged by the charger 22 to form an electrostatic latent image on the photoreceptor drum 21. Furthermore, each toner image forming unit 20 includes a developing device 24 that develops the electrostatic latent image formed on the photoreceptor drum 21 by the exposure device 23 to form a toner image, and a blade 25 that removes toner remaining on the surface of the photoreceptor drum 21 after the toner image has been transferred to the transfer device 30.

[0033] The charger 22, for example, negatively charges the surface (photosensitive layer) of the photoreceptor drum 21. The negatively charged surface of the photoreceptor drum 21 exhibits positive polarity in the area irradiated with exposure light L by the exposure device 23, and an electrostatic latent image is formed on the surface of the photoreceptor drum 21. Then, toner that has been negatively frictionally charged in the developing device 24 adheres to the positively polarized electrostatic latent image, and the electrostatic latent image is developed. In this way, a toner image is formed on the surface (outer surface) of the photoreceptor drum 21. The blade 25 contacts the surface of the photoreceptor drum 21 and scrapes off any toner remaining on the surface of the photoreceptor drum 21.

[0034] The yellow (Y), magenta (M), cyan (C), and black (K) toners used in the toner image forming units 20Y, 20M, 20C, and 20K (hereinafter referred to as 20Y to 20K) are composed of pigment and binder resin.

[0035] [Transfer device 30] The transfer device 30 performs primary transfer by superimposing the toner images of each color photoreceptor drum 21 onto the intermediate transfer belt 31, and then secondary transfers the superimposed toner images to the recording medium P at the secondary transfer position NT (an example of a nip). Specifically, as shown in Figure 1, the transfer device 30 comprises an endless belt-shaped intermediate transfer belt 31, a primary transfer roll 33, a secondary transfer belt 36 as an example of a toner transporter which is a transfer member, a cleaning device 35 for cleaning the surface of the intermediate transfer belt 31, and a cleaning device 60, which is the main part of the first embodiment, for cleaning the surface of the secondary transfer belt 36. The cleaning device 60 will be described later.

[0036] The transfer device 30 has a detection unit (sensor) 49 for detecting density detection images (patches) and color misalignment detection images (patches), which is located downstream of the toner image forming unit 20(K) (on the left side in Figure 1).

[0037] [Intermediate transfer belt 31] As shown in Figure 1, the intermediate transfer belt 31 is endless and its orientation is determined by being wrapped around multiple rolls 32. In the first embodiment, the intermediate transfer belt 31 is positioned as an inverted obtuse triangle, which is long in the width direction of the device when viewed from the front. Of the multiple rolls 32, roll 32D shown in Figure 1 functions as a drive roll that rotates the intermediate transfer belt 31 in the direction of arrow A using the power of a motor (not shown). By rotating in the direction of arrow A, the intermediate transfer belt 31 transports the primary transferred image to the secondary transfer position NT.

[0038] Furthermore, among the multiple rolls 32, roll 32T shown in Figure 1 functions as a tension-applying roll that applies tension to the intermediate transfer belt 31. Among the multiple rolls 32, roll 32B shown in Figure 1 functions as a counter roll to the secondary transfer roll 34. The upper end of the intermediate transfer belt 31, which is positioned in an inverted obtuse-angled triangular shape as described above, is wrapped around the counter roll 32B, forming the obtuse angle at the lower end. The intermediate transfer belt 31, in the above-described position, is in contact with the photosensitive drums 21 of each color from below at its upper edge that extends in the width direction of the apparatus.

[0039] [Primary Transfer Roll 33] As shown in Figure 1, the primary transfer roll 33 is a roll that transfers the toner image of each photoreceptor drum 21 to the intermediate transfer belt 31, and is positioned inside the intermediate transfer belt 31. Each primary transfer roll 33 is positioned opposite the corresponding color photoreceptor drum 21, with the intermediate transfer belt 31 in between. Furthermore, a primary transfer voltage with the opposite polarity to the toner polarity is applied to the primary transfer roll 33 by a power supply unit (not shown). By applying this primary transfer voltage, the toner image formed on the photoreceptor drum 21 is transferred to the intermediate transfer belt 31 at the primary transfer position T between the photoreceptor drum 21 and the primary transfer roll 33.

[0040] [Secondary transfer belt 36] The secondary transfer belt 36 is a belt that transfers the toner image superimposed on the intermediate transfer belt 31 to the recording medium P. As shown in Figures 1 and 3, the secondary transfer belt 36 is endless and is wound around the secondary transfer roll 34 and the driven roll 37.

[0041] The secondary transfer roll 34 is positioned to sandwich the intermediate transfer belt 31 and the secondary transfer belt 36 between it and the opposing roll 32B, with the secondary transfer belt 36 and the intermediate transfer belt 31 in contact with a predetermined load. The space between the secondary transfer belt 36 and the intermediate transfer belt 31 in this contact is defined as the secondary transfer position NT. A recording medium P is supplied to this secondary transfer position NT from the housing 51 in a timely manner. The secondary transfer belt 36 is moved in a circular motion in the direction of arrow B as the secondary transfer roll 34 is rotated (see Figure 3).

[0042] In the first embodiment, as shown in Figure 1, when transferring the toner image from the intermediate transfer belt 31 to the recording medium P, a negative polarity voltage is applied to the opposing roll 32B by the power supply unit 39. This creates a potential difference between the opposing roll 32B and the secondary transfer roll 34. That is, by applying a negative polarity voltage to the opposing roll 32B, a secondary transfer voltage (positive polarity voltage) with the opposite polarity to the toner is indirectly applied to the secondary transfer roll 34, which forms the opposing electrode of the opposing roll 32B. As a result, the toner image of the negative electrode is transferred from the intermediate transfer belt 31 to the recording medium P as it passes through the secondary transfer position NT.

[0043] On the other hand, when the toner on the intermediate transfer belt 31 is to be held on the intermediate transfer belt 31 as it passes through the secondary transfer position NT, a positive voltage is applied to the opposing roll 32B by the power supply unit 39. This creates a potential difference between the opposing roll 32B and the secondary transfer roll 34. In other words, by applying a positive voltage to the opposing roll 32B, a non-transfer voltage (negative voltage) with the same polarity as the toner is indirectly applied to the secondary transfer roll 34, which forms the opposing electrode of the opposing roll 32B. As a result, the toner passing through the secondary transfer position NT is held on the intermediate transfer belt 31 by a repulsive force from the secondary transfer roll 34.

[0044] [Cleaning device 35 for the intermediate transfer belt 31] As shown in Figure 1, the cleaning device 35 is positioned downstream of the secondary transfer position NT and upstream of the primary transfer position T(Y) in the circumferential direction of the intermediate transfer belt 31. The cleaning device 35 is equipped with a blade 351 that scrapes off toner remaining on the surface of the intermediate transfer belt 31.

[0045] <Operation of the image forming apparatus 10> Now, let's explain the operation of the image forming apparatus 10.

[0046] When the control unit 70 receives an image forming command (print command), the control unit 70 operates the toner image forming units 20Y~20K, the transfer device 30, and the fixing device 40 as follows (see Figure 1).

[0047] In the toner image forming units 20Y to 20K, the photoreceptor drums 21 of each color are charged by the charger 22 while rotating. Each charged photoreceptor drum 21 is exposed by each exposure device 23, and an electrostatic latent image is formed on the surface of each photoreceptor drum 21. The electrostatic latent image formed on each photoreceptor drum 21 is developed by a developer supplied from the developing device 24. As a result, toner images for yellow (Y), magenta (M), cyan (C), and black (K) are formed on the photoreceptor drums 21Y to 21K for the other colors, respectively.

[0048] The toner images of each color formed on each photoreceptor drum 21 are sequentially transferred by each primary transfer roll 33 to the transfer area (not shown) of the circulating intermediate transfer belt 31.

[0049] The toner image transferred to the intermediate transfer belt 31 is transported to the secondary transfer position NT by the rotation of the intermediate transfer belt 31.

[0050] At this secondary transfer position NT, the recording medium P is supplied by the transport roll 52 in accordance with the timing of toner image transport. As the recording medium P and toner image pass through this secondary transfer position NT, a secondary transfer voltage (positive polarity voltage) is applied to the secondary transfer roll 34 via the opposing roll 32B. As a result, the toner image is transferred from the intermediate transfer belt 31 to the recording medium P.

[0051] The recording medium P onto which the toner image has been transferred is transported by the transport belt 58 from the secondary transfer position NT to the fuser 40, where the toner image on the recording medium P is fixed to the recording medium P.

[0052] The toner images formed by the toner image forming units 20Y to 20K include transfer images for transfer to the recording medium P and non-transfer images that are not transferred to the recording medium P. Non-transfer images include density detection images (patches), color shift detection images (patches), images for consuming degraded developer (toner) (bands), and images for supplying toner between the photoreceptor drum 21 and the blade 25 (bands).

[0053] In the case of a normal transfer image, the toner image from each toner image forming unit 20 is transferred by each primary transfer roll 33 to a transfer area (not shown) on the intermediate transfer belt 31. The toner image transferred to the intermediate transfer belt 31 passes through the secondary transfer position NT together with the recording medium P and is transferred to the recording medium P.

[0054] At this time, as described above, a positive polarity secondary transfer voltage (a voltage with the opposite polarity to the toner) is applied to the secondary transfer roll 34 via the opposing roll 32B, and the toner image that passes through the secondary transfer position NT together with the recording medium P is transferred from the intermediate transfer belt 31 to the recording medium P.

[0055] On the other hand, in the case of non-transfer images such as patches, the patches of each toner image forming unit 20 are transferred to a non-transfer area (not shown) on the intermediate transfer belt 31 by each primary transfer roll 33. The patches transferred onto the intermediate transfer belt 31 pass through the secondary transfer position NT independently, without passing through the secondary transfer position NT together with the recording medium P.

[0056] At this time, a negative non-transfer voltage (a voltage with the same polarity as the toner polarity) is applied to the secondary transfer roll 34 via the opposing roll 32B so that the patch on the intermediate transfer belt 31 is held on the intermediate transfer belt 31. As a result, the toner of the patch on the intermediate transfer belt 31 receives a repulsive force from the secondary transfer belt 36 (secondary transfer roll 34) and is held on the intermediate transfer belt 31. The toner of the patch held on the intermediate transfer belt 31 is transported to the cleaning device 35 and removed from the intermediate transfer belt 31 by the cleaning device 35.

[0057] <Cleaning device 60 for secondary transfer belt 36> Next, the cleaning device 60, which is the main component of the first embodiment, will be described.

[0058] (Configuration of cleaning device 60) As shown in Figure 3, the cleaning device 60 has a cleaning brush 61 that rotates while in contact with the secondary transfer belt 36 and removes toner adhering to the secondary transfer belt 36. Note that "removing toner adhering to the belt" is synonymous with "cleaning the belt to which toner has adhered." The secondary transfer belt 36 is an example of a toner transporter, which is a transfer member, and an example of a member to be cleaned, as described above.

[0059] Furthermore, the cleaning device 60 includes a first contact member 64 that contacts the bristles 61F of the cleaning brush 61, and a second contact member 66 that contacts the bristles 61F of the cleaning brush 61 downstream of the first contact member 64 in the rotational direction of the cleaning brush 61.

[0060] Furthermore, the cleaning device 60 includes a housing 69 that accommodates a cleaning brush 61, a first contact member 64, and a second contact member 66.

[0061] [Cleaning brush 61] The cleaning brush 61 has a metal shaft portion 61A and a synthetic resin brush portion 61B that is provided around the entire circumference of the shaft portion 61A. In the brush portion 61B, numerous bristles 61F extend radially (radially outward) from the shaft portion 61A. In the first embodiment, the radial lengths of the numerous bristles 61F are equal. The tip ends of some of the bristles 61F in the brush portion 61B are in contact with the secondary transfer belt 36.

[0062] The cleaning brush 61 rotates when its shaft portion 61A is driven by a rotational drive unit (not shown). For example, the cleaning brush 61 rotates in the opposite direction to the circumferential direction of the secondary transfer belt 36 (clockwise as indicated by arrow D in Figure 3) at the contact point with the secondary transfer belt 36.

[0063] [First contact member 64] As shown in Figures 3 and 4, the first contact member 64 is in contact with the bristles 61F of the cleaning brush 61 while its relative position to the cleaning brush 61 remains unchanged. The first contact member 64 has a shape in which at least the portion that contacts the bristles 61F is curved in a convex shape along the circumferential direction of the cleaning brush 61. As an example, the first contact member 64 is made of a cylindrical member. Note that in Figures 3 and 4, a portion of the bristles 61F of the cleaning brush 61 is shown for clarity.

[0064] In the first embodiment, the first contact member 64 is supported by a support portion 80 provided on the housing 69, while the relative position between the axial center of the first contact member 64 and the center of the shaft portion 61A of the cleaning brush 61 (axial center 61C shown in Figure 4) remains unchanged.

[0065] The cleaning device 60 is equipped with a rotating part 65 that rotates the first contact member 64. The rotating part 65 is composed of, for example, a motor. The rotating part 65 rotates the first contact member 64 at the point where it faces the cleaning brush 61, such that the rotation direction of the cleaning brush 61 and the rotation direction of the first contact member 64 are in opposite directions. That is, the first contact member 64 rotates clockwise as shown by arrow E. The first contact member 64 is rotatably supported by a support part 80 via a bearing (not shown).

[0066] For example, the penetration of the bristles 61F of the cleaning brush 61 is smaller than the radius of the first contact member 64. The bristles 61F of the cleaning brush 61 are in contact with the outer surface of the first contact member 64 in an area narrower than half (a semicircle) of the outer surface of the first contact member 64. In other words, the tip of the bristles 61F is closer to the axial center 61C of the cleaning brush 61 than the point of contact P1 of the tangent line L1 drawn from the axial center 61C of the shaft portion 61A of the cleaning brush 61 to the first contact member 64. Furthermore, because the first contact member 64 is made of a cylindrical member, when toner adheres to the outer surface of the first contact member 64, the toner is more likely to fall off from the outer surface of the first contact member 64.

[0067] [Second contact member 66] As shown in Figures 3 and 4, the second contact member 66 is in contact with the bristles 61F of the cleaning brush 61 while its relative position to the cleaning brush 61 remains unchanged. The second contact member 66 has a shape in which at least the portion that contacts the bristles 61F is curved in a convex shape along the circumferential direction of the cleaning brush 61. For example, the second contact member 66 is made of a cylindrical member. For example, the outer diameter of the second contact member 66 is the same as the outer diameter of the first contact member 64, but the outer diameter of the second contact member 66 may be different from the outer diameter of the first contact member 64.

[0068] In the first embodiment, the second contact member 66 is supported by the support portion 80 of the housing 69, with no change in the relative position between the axial center of the second contact member 66 and the axial center 61C of the cleaning brush 61.

[0069] In the first embodiment, the second contact member 66 is configured not to rotate. Furthermore, since the second contact member 66 is a cylindrical member, when toner adheres to the outer surface of the second contact member 66, the toner easily falls off from the outer surface of the first contact member 64.

[0070] As shown in Figure 4, the second contact member 66 is positioned on the extension line EL between the base portion 62 of the bristles 61F and the axial center 61C of the cleaning brush 61 when it is separated from the first contact member 64. In the first embodiment, the extension line EL between the base portion 62 of the bristles 61F and the axial center 61C of the cleaning brush 61 when it is separated from the first contact member 64 is a tangent line that contacts the outer circumferential surface of the second contact member 66.

[0071] Furthermore, in the first embodiment, the amount of penetration of the second contact member 66 into the bristles 61F of the cleaning brush 61 is equivalent to the amount of penetration of the first contact member 64 into the bristles 61F of the cleaning brush 61.

[0072] [Cabinet 69] The housing 69 has a recessed portion that houses the cleaning brush 61, the first contact member 64, and the second contact member 66, with the cleaning brush 61, the first contact member 64, and the second contact member 66 positioned on the upper side in the vertical direction of the housing 69. As a result, toner that falls from the cleaning brush 61, the first contact member 64, and the second contact member 66 is stored in the recessed portion of the housing 69.

[0073] As described above, the housing 69 is provided with a support portion 80 that supports the first contact member 64 and the second contact member 66. The support portion 80 is electrically insulated.

[0074] <Operation and Effects of the First Embodiment> Next, the operation and effects of the first embodiment will be described.

[0075] In the image forming apparatus 10 shown in Figure 1, when a patch, which is a non-transfer image, is formed on the surface of the intermediate transfer belt 31, a non-transfer voltage is applied, but the secondary transfer belt 36 and the intermediate transfer belt 31 are in contact with a predetermined load. Therefore, some of the toner from the patch on the surface of the intermediate transfer belt 31 may be transferred to the secondary transfer belt 36 even if subjected to electrostatic repulsion. As a result, toner adheres to the secondary transfer belt 36.

[0076] Furthermore, even when a toner image, which is a transfer image, is formed on the surface of the intermediate transfer belt 31, a portion of the toner image on the surface of the intermediate transfer belt 31 may not be transferred to the recording medium P and may instead adhere to the secondary transfer belt 36.

[0077] As shown in Figure 3, toner adhering to the secondary transfer belt 36 is transported to the cleaning device 60 as the secondary transfer belt 36 rotates. The cleaning device 60 is equipped with a cleaning brush 61 that rotates while in contact with the secondary transfer belt 36, and toner adhering to the surface of the secondary transfer belt 36 is removed by the cleaning brush 61. For example, toner is attracted to the cleaning brush 61 by static electricity or the like.

[0078] For example, if toner removed by the cleaning brush 61 accumulates or remains inside the cleaning brush 61, there is a concern that the toner removal performance of the cleaning brush 61 will decrease, leading to toner contamination on the back surface of the recording medium P.

[0079] Figures 5(A) to 5(C) show the process by which toner adsorbed on the cleaning brush 61 is removed in the cleaning device 60. In Figures 5(A) to 5(C), a portion of the bristles 61F of the cleaning brush 61 is shown to make the process of removing toner T from the bristles 61F of the cleaning brush 61 easier to understand.

[0080] As shown in Figure 5(A), as the cleaning brush 61 rotates in the direction of arrow D, the tip of the bristles 61F of the cleaning brush 61 moves away from the secondary transfer belt 36 and then comes into contact with the first contact member 64 (see Figure 3). Toner T is adsorbed onto the bristles 61F of the cleaning brush 61.

[0081] As shown in Figure 5(B), when the cleaning brush 61 rotates in the direction of arrow D, the first contact member 64 rotates in the opposite direction (direction of arrow E) at the contact point with the cleaning brush 61, causing the bristles 61F of the cleaning brush 61 to contact the first contact member 64 and bend. Then, due to the rotation of the cleaning brush 61 and the first contact member 64, the bending deformation of the bristles 61F gradually increases.

[0082] As shown in Figure 5(C), the cleaning brush 61 rotates further in the direction of arrow D, and the first contact member 64 rotates further in the opposite direction to the cleaning brush 61 (in the direction of arrow E). As a result, the tip of the bristles 61F of the cleaning brush 61 separates from the first contact member 64, and as the bristles 61F recover from their deflection, the tip of the bristles 61F of the cleaning brush 61 comes into contact with the second contact member 66. Note that the period as the bristles 61F recover from their deflection (i.e., during the recovery from deflection) is synonymous with "the release operation as the bristles 61F are released from their deflection." At this time, the impact force acting on the bristles 61F increases as the bristles 61F come into contact with the second contact member 66, causing the toner T to fall from the bristles 61F. In other words, a large impact force is generated on the bristles 61F, causing the toner T to be shaken off.

[0083] Here, we will explain the comparative example cleaning device 200 using Figure 7.

[0084] As shown in Figure 7, the comparative example cleaning device 200 includes a cleaning brush 61 and a first contact member 64 that contacts the cleaning brush 61. The comparative example cleaning device 200 does not have a second contact member 66 like the cleaning device 60 of the first embodiment. The other components of the cleaning device 200 are the same as those of the cleaning device 60 of the first embodiment.

[0085] As shown in Figure 7(A), when the cleaning brush 61 rotates in the direction of arrow D, the tip of the bristles 61F of the cleaning brush 61 comes into contact with the first contact member 64.

[0086] As shown in Figure 7(B), when the cleaning brush 61 rotates in the direction of arrow D, the first contact member 64 rotates in the opposite direction (direction of arrow E) at the contact point with the cleaning brush 61. As a result, the bristles 61F of the cleaning brush 61 come into contact with the first contact member 64 and bend, and the bending deformation of the bristles 61F gradually increases.

[0087] As shown in Figure 7(C), as the cleaning brush 61 rotates further in the direction of arrow D, and the first contact member 64 rotates further in the opposite direction to the cleaning brush 61 (in the direction of arrow E), the tip of the bristles 61F of the cleaning brush 61 separates from the first contact member 64, and the bristles 61F recover from their bending deformation. When the bristles 61F recover from their bending deformation, some of the toner T falls off the bristles 61F.

[0088] In the comparative example cleaning device 200, the tip of the bristles 61F of the cleaning brush 61 is separated from the first contact member 64, and the bristles 61F do not come into contact with other members while they are recovering from their bending deformation. As a result, no large impact force acts on the bristles 61F of the cleaning brush 61, and the toner T is less likely to detach from the bristles 61F.

[0089] In contrast, in the cleaning device 60 of the first embodiment, as shown in Figure 3, a second contact member 66 is provided that contacts the bristles 61F of the cleaning brush 61 downstream of the first contact member 64 in the rotational direction of the cleaning brush 61. The second contact member 66 is positioned on the extension line EL between the base portion 62 of the bristles 61F of the cleaning brush 61 when it separates from the first contact member 64 and the axial center 61C of the cleaning brush 61. As a result, as shown in Figures 5(B) and (C), the tip end of the bristles 61F of the cleaning brush 61 separates from the first contact member 64 and contacts the second contact member 66 while the bristles 61F are recovering from their deflection deformation. Therefore, the impact force acting on the bristles 61F is increased, making it easier for toner T to fall from the bristles 61F. Consequently, toner T is less likely to accumulate or remain in the cleaning brush 61.

[0090] Therefore, compared to a configuration in which the bristles of the cleaning brush recover from deformation caused by contact with an upstream contact member before contacting a downstream contact member, the cleaning device 60 can suppress a decrease in the toner removal performance.

[0091] Furthermore, in the cleaning device 60, the first contact member 64 and the second contact member 66 are shaped such that at least the portion that contacts the bristles 61F of the cleaning brush 61 is curved in a convex shape along the circumferential direction of the cleaning brush 61.

[0092] Therefore, in the cleaning device 60, the bristles 61F are more likely to bend when they come into contact with the first contact member 64 and the second contact member 66 due to the rotation of the cleaning brush 61, compared to the case where the first contact member and the second contact member are rectangular in shape.

[0093] Furthermore, in the cleaning device 60, at least one of the first contact member 64 and the second contact member 66 is a cylindrical member.

[0094] Therefore, in the cleaning device 60, positioning of the first contact member 64 and the second contact member 66 is easier compared to a device where only a portion of the first contact member and the second contact member have a circular shape.

[0095] Furthermore, in the cleaning device 60, the first contact member 64 is a cylindrical member and is equipped with a rotating part 65 that rotates the first contact member 64. At the point where the first contact member 64 and the cleaning brush 61 face each other, the rotation direction of the cleaning brush 61 and the rotation direction of the first contact member 64 are in opposite directions.

[0096] Therefore, in the cleaning device 60, compared to the case where the first contact member, which is a cylindrical member, is fixed, toner T is more easily removed from the bristles 61F of the cleaning brush 61.

[0097] Furthermore, in the cleaning device 60, the first contact member 64 is a cylindrical member, and the penetration of the bristles 61F of the cleaning brush 61 is smaller than the radius of the first contact member 64.

[0098] Therefore, in the cleaning device 60, the impact is greater when the bristles 61F of the cleaning brush 61 move away from the first contact member 64 and hit the second contact member 66, compared to the case where the penetration of the cleaning brush bristles is greater than the radius of the cylindrical member.

[0099] Furthermore, in the cleaning device 60, the amount of penetration of the second contact member 66 into the bristles 61F is equivalent to the amount of penetration of the first contact member 64 into the bristles 61F.

[0100] Therefore, in the cleaning device 60, the amount of deflection of the bristles 61F when the first contact member 64 contacts the bristles 61F is greater than or equal to the amount of deflection of the bristles 61F when the second contact member 66 contacts the bristles 61F. As a result, the impact when the bristles 61F, released from contact with the first contact member 64, hit the first contact member 66 can be increased compared to the case where the amount of penetration of the second contact member into the bristles is greater than the amount of penetration of the first contact member into the bristles.

[0101] Furthermore, in the cleaning device 60, the support portion 80 that supports the first contact member 64 and the second contact member 66 is electrically insulated.

[0102] Therefore, in the cleaning device 60, compared to the case where the support portion supporting the first contact member and the second contact member is charged, the adhesion of charged toner from the support portion 80 to the first contact member 64 and the second contact member 66 is suppressed.

[0103] Furthermore, the image forming apparatus 10 is provided with a cleaning device 60 for cleaning the toner T that has adhered to the secondary transfer belt 36.

[0104] Therefore, in the image forming apparatus 10, compared to a configuration in which the bristles of the cleaning brush recover from deformation caused by contact with an upstream contact member before contacting a downstream contact member, the occurrence of contamination of the recording medium P by toner T is suppressed.

[0105] [Second Embodiment] Next, an image forming apparatus equipped with a cleaning device according to the second embodiment will be described. Note that components identical to those in the first embodiment described above will be given the same part numbers and their descriptions will be omitted.

[0106] Figure 6 shows a part of the image forming apparatus 100 equipped with a cleaning device 110. As shown in Figure 6, the image forming apparatus 100 includes an intermediate transfer belt 101 to which the toner image of the toner image forming unit (not shown) is transferred. In the first embodiment, the cleaning device 60 was used to clean the secondary transfer belt 36, but in the second embodiment, a cleaning device 110 is provided to clean the intermediate transfer belt 101. The intermediate transfer belt 101 is an example of a toner transporter, which is a toner holding member that holds the toner image.

[0107] The cleaning device 110 comprises a cleaning brush 61, a first contact member 64, and a second contact member 66. Furthermore, the cleaning device 110 includes a housing 112 that accommodates the cleaning brush 61, the first contact member 64, and the second contact member 66. The other configurations are the same as those of the cleaning device 60 of the first embodiment.

[0108] The cleaning device 110 can achieve the same effect as the cleaning device 60 of the first embodiment by having the same configuration.

[0109] [others] Although the first and second embodiments have been described above, this disclosure is not limited to those described above, and it goes without saying that it can be implemented in various modified forms without departing from its spirit.

[0110] For example, in an image forming apparatus without a secondary transfer belt 36, where the recording medium P is nipped by a secondary transfer roll 34 and an intermediate transfer belt 31, the secondary transfer roll 34 becomes the toner transport body of this disclosure. In this case, although not shown in the figures, a cleaning device 60 or a cleaning device 110 can be provided opposite the secondary transfer roll 34, thereby allowing the toner adhering to the secondary transfer roll 34 to be cleaned by the cleaning device 60 or the cleaning device 110.

[0111] Furthermore, in the first and second embodiments, the extension line EL between the base portion 62 of the bristles 61F and the axial center 61C of the cleaning brush 61 when it moves away from the first contact member 64 is in contact with the outer circumferential surface of the first contact member 64. However, this disclosure is not limited to this configuration. For example, the second contact member 66 may be positioned in a region that overlaps with the extension line EL between the base portion 62 of the bristles 61F and the axial center 61C of the cleaning brush 61 when it moves away from the first contact member 64.

[0112] Furthermore, in the first and second embodiments, the cleaning brush 61 may be rotated in the same direction as the circumferential direction of the secondary transfer belt 36 or intermediate transfer belt 101 at the contact portion with the secondary transfer belt 36 or intermediate transfer belt 101. In this case, for example, the cleaning brush 61 is configured to rotate with a peripheral speed difference from the peripheral speed of the secondary transfer belt 36 or intermediate transfer belt 101.

[0113] Furthermore, in the first and second embodiments, the second contact member 66 is configured not to rotate, but a rotating part may be provided to rotate the second contact member 66. When the second contact member 66 is rotated, the rotation direction of the cleaning brush 61 and the rotation direction of the second contact member 66 may be configured to be opposite at the point where the second contact member 66 and the cleaning brush 61 face each other. In such a configuration, toner is more easily removed from the bristles 61F of the cleaning brush 61 compared to the case where the cylindrical second contact member is fixed.

[0114] Furthermore, in the first and second embodiments, the first contact member 64 and the second contact member 66 are cylindrical members, but the disclosure is not limited to this configuration. For example, if the second contact member 66 is not rotated, the second contact member 66 may have a fan-shaped or semi-circular shape, where the portion that contacts the bristles 61F of the cleaning brush 61 is curved convexly along the circumferential direction of the cleaning brush 61.

[0115] Furthermore, although the first contact member 64 is rotated in the first and second embodiments, the configuration may also be one in which the first contact member 64 is not rotated. In this case, the first contact member 64 may have a fan-shaped or semi-circular shape in which the part that contacts the bristles 61F of the cleaning brush 61 is curved convexly along the circumferential direction of the cleaning brush 61.

[0116] Furthermore, in the first and second embodiments, the amount of penetration of the second contact member 66 into the bristles 61F of the cleaning brush 61 is equivalent to the amount of penetration of the first contact member 64 into the bristles 61F of the cleaning brush 61, but the disclosure is not limited to this configuration. For example, the amount of penetration of the second contact member 66 into the bristles 61F of the cleaning brush 61 may be smaller than the amount of penetration of the first contact member 64 into the bristles 61F of the cleaning brush 61. In such a configuration, the amount of deflection of the bristles 61F when the first contact member 64 contacts the bristles 61F is greater than or equal to the amount of deflection of the bristles 61F when the second contact member 66 contacts the bristles 61F. As a result, the impact when the bristles 61F, released from contact with the first contact member 64, hit the first contact member 66 can be increased compared to the case where the amount of penetration of the second contact member into the bristles is greater than the amount of penetration of the first contact member into the bristles.

[0117] Furthermore, in the first and second embodiments, no voltage is applied to the cleaning brush 61, but a power supply unit may be provided that applies a positive bias voltage to the shaft portion 61A of the cleaning brush 61. This makes it easier for toner to be attracted to the cleaning brush 61 from the member to be cleaned when the cleaning brush 61 rotates while in contact with the member to be cleaned. [Explanation of symbols]

[0118] 10 Image forming apparatus 36. Secondary transfer belt (an example of a toner transporter, which is a transfer component) 60 Cleaning equipment 61 Cleaning brush 61C Axis center 61F Hair material 62. Root part 64 First contact member 65 Rotating part 66 Second contact member 80 Support part 100 Image forming apparatus 101 Intermediate transfer belt (an example of a toner transporter, which is a toner holding component) 110 Cleaning equipment EL extension line P recording medium T Toner

Claims

1. A cleaning brush having numerous bristles that rotate and contact the surface of the member to be cleaned to which toner is attached, and which removes the toner attached to the surface of the member to be cleaned, A first contact member that contacts the bristles without changing its relative position to the cleaning brush, A second contact member is located downstream of the first contact member in the rotational direction of the cleaning brush and contacts the bristles without changing its relative position to the cleaning brush, the second contact member being positioned on the extension line between the base of the bristles and the axial center of the cleaning brush when it separates from the first contact member, It has, The first contact member is a cylindrical member, and it is equipped with a rotating part for rotating the cylindrical member, At the portion facing the cleaning brush, the rotation direction of the cleaning brush and the rotation direction of the first contact member are in opposite directions. The second contact member is a cylindrical member and is configured not to rotate. A cleaning device in which the amount of penetration of the second contact member into the bristles is smaller than the amount of penetration of the first contact member into the bristles.

2. The cleaning device according to claim 1, wherein the penetration of the bristles is smaller than the radius of the cylindrical member constituting the first contact member.

3. The cleaning device according to claim 1 or claim 2, wherein the support portion that supports the first contact member and the second contact member is electrically insulated.

4. A toner transporter which is a toner holding member that holds a toner image, or a transfer member that transfers a toner image to a recording medium nipped between itself and the toner holding member, A cleaning device according to any one of claims 1 to 3 for cleaning toner adhering to the surface of the toner transporter, An image forming apparatus having

Images